Method for providing a game, recording medium and server

ABSTRACT

A method for providing a game in which a plurality of missions is presented to a user device each time a certain period has elapsed from a server having a storage unit for storing user information relating to a plurality of users, includes the steps of generating a plurality of different missions for each of the plurality of users based on the user information stored in the storage unit, presenting a list of the generated missions for each of the users on the user device, and presenting an operational element for updating a mission included in the presented list to another mission regardless of the elapse of the period in accordance with the progress of presented missions.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.14/109,704, filed Dec. 17, 2013, which claims benefit of JP 2013-129889,filed on Jun. 20, 2013. The entire contents of which are herebyincorporated by reference.

TECHNICAL FIELD

The present invention relates to a method for providing a game, arecording medium, and a server.

BACKGROUND

In recent years, a server which provides a game to portable devices viaa communication network has spread. The game provided by the serverincludes one in which a plurality of users can participate (a so-called“social game”), in which the users can not only battle and cooperatewith each other but also communicate with each other.

As an example of such a social game, Patent Gazette No. JP5118261describes a game in which a user battles with an enemy character byusing a card (a so-called “card battle game”). In the card battle game,a user battles with an enemy character prepared on a game program byusing a card while cooperating with another user. In such a game, a usercan acquire an item by clearing a mission generated in the game, and canstrengthen his/her card by using the item.

SUMMARY

Generally, a game includes a plurality of missions. The missions are thesame for all users, and the number of missions to be presented islimited. Thus, the user is not able to try various missions. Moreover,items which can be acquired by clearing the missions are generally notclearly presented. Therefore, the user only tries all the missions toacquire the item he/she wants. Thus, a conventional game is not sointeresting for the user, and the user may lose interest in continuingthe game.

An object of the present invention is to increase chances for a user toselect a mission, and to maintain and increase the user's interest incontinuing a game.

Provided is a method for providing a game in which a plurality ofmissions is presented to a user device each time a certain period haselapsed from a server having a storage unit for storing user informationrelating to a plurality of users. The method includes the steps ofgenerating a plurality of different missions for each of the pluralityof users based on the user information stored in the storage unit,presenting a list of the generated missions for each of the users on theuser device, and presenting an operational element for updating amission included in the presented list to another mission, regardless ofthe elapse of the period in accordance with the progress of presentedmissions.

Preferably, the above method further includes the step of updating amission included in the presented list to another mission generated fora corresponding user in response to operation of the operationalelement.

Preferably, in the above method, the storage unit stores informationabout another user associated with each of the plurality of users as theuser information, and the step of presenting the list includes the stepof presenting, along with the missions generated for a first user, amission presented on a second user device of a second user associatedwith the first user, on the user device of the first user.

Preferably, the above method further includes the step of notifying thesecond user device that the mission presented on the second user devicehas also been presented on the user device of the first user.

Preferably, in the above method, the storage unit stores informationabout the time when each of a plurality of users has most recentlyplayed the game, as the user information, and the step of presenting thelist includes the step of preferentially selecting, out of the pluralityof other users associated with the first user, a device of a user whohas not played the game for a longer time, as the second user device.

Preferably, in the above method, the step of presenting the listincludes the step of presenting the mission presented on the second userdevice, on the user device of the first user only within a certainperiod.

Preferably, in the above method, the step of presenting the listincludes the step of presenting the generated mission for each of theusers and an item which can be acquired by the user by clearing themission, on the user device in association with each other.

Provided is a non-transitory recording medium that has recorded acontrol program of a server, the server having a storage unit forstoring user information relating to a plurality of users, for providinga game in which a plurality of missions is presented each time a certainperiod has elapsed to a user device. The control program causes theserver to execute a process, the process including generating aplurality of different missions for each of the plurality of users basedon the user information stored in the storage unit, presenting a list ofthe generated missions for each of the users on the user device, andpresenting an operational element for updating a mission included in thepresented list to another mission regardless of the elapse of the periodin accordance with the progress of presented missions.

Provided is a server for providing a game in which a plurality ofmissions is presented each time a certain period has elapsed to aplurality of user devices. The server includes a storage unit forstoring user information relating to a plurality of users, a generationunit for generating a plurality of different missions for each of theplurality of users based on the user information stored in the storageunit, and a listing unit for presenting a list of the missions for eachof the users generated by the generation unit on the user devices. Thelisting unit presents an operational element for updating a missionincluded in the presented list to another mission, regardless of theelapse of the period in accordance with the progress of presentedmissions.

According to the above method for providing a game, the recording mediumand the server, it is possible to increase the chances of a userselecting a mission, and maintaining and increasing the user's interestin continuing a game.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present optical device will beapparent from the ensuing description, taken in conjunction with theaccompanying drawings, in which:

FIG. 1 illustrates an example of a schematic configuration of a gamesystem;

FIG. 2 illustrates an example of a schematic configuration of theportable device;

FIG. 3 illustrates an example of a schematic configuration of theserver;

FIGS. 4A to 4C illustrate examples of data structures of the varioustypes of tables.

FIGS. 5A to 5F illustrate examples of a display screen of the portabledevice;

FIG. 6 illustrates an example of an operation sequence of the gamesystem;

FIGS. 7A and 7B illustrate an example of an operation flow of theserver; and

FIG. 8 illustrates an example of an operation flow of the server.

DESCRIPTION

Hereinafter, with reference to the drawings, a method for providing agame, a recording medium, and a server will be described. It should benoted that the technical scope of the present invention is not limitedto embodiments of the invention, but covers the invention described inthe claims and its equivalent.

A game system described below provides a social game in which aplurality of users (players) can participate and a plurality of newmissions is presented each time a certain period has elapsed. When theperiod is 24 hours, for example, a new mission is automaticallypresented to the users every day in the game system described below.“Mission” means a constituent element of a game called “quest”,“dungeon” or the like which allows the users to acquire an item and thelike by clearing a mission. The mission is, for example, to explore adungeon, battle with an enemy character, and acquire an item in thedungeon. The user plays the game while clearing a plurality of missionsto collect desired items with his/her own portable device.

The game may be, for example, a mini game provided in a card battle gamefor battling with an enemy character by using a card. In this case, theitem can be used to strengthen a card for a card battle, for example.The user can advantageously play the card battle by strengtheninghis/her own card by using the items collected in the plurality ofmissions.

Each of the portable devices requires a mission list for each of theusers to select a mission of a server in response to an operationperformed by the user. Consequently, the server presents a mission listgenerated for each of the users in which different missions are listed,to a corresponding portable device of the user. The server updates themissions included in the mission list to other missions in response to arequest from the portable device. Thus, a user who has cleared themissions quickly can select a new mission without waiting, for example,24 hours. Therefore, the chances of the user selecting the missionsincrease, making it possible to maintain and increase the user'sinterest in continuing the game.

FIG. 1 illustrates an example of a schematic configuration of a gamesystem 1.

The game system 1 includes at least one portable device 2 and a server3. The portable device 2 and the server 3 are connected to each othervia a communication network, and are connected to each other, forexample, via a base station 4, a mobile communication network 5, agateway 6, and the Internet 7. A program to be executed by the portabledevice 2 (e.g., a browsing program) and a program to be executed by theserver 3 (e.g., a game program) communicate with each other by using acommunication protocol such as a Hypertext Transfer Protocol (HTTP).

FIG. 2 illustrates an example of a schematic configuration of theportable device 2.

The portable device 2 is connected to the server 3 via the base station4, the mobile communication network 5, the gateway 6, and the Internet7, to communicate with the server 3. The portable device 2 requests theprogress of a game of the server 3 in response to an operation of anoperation unit 23 (e.g., a button) by a user. The portable device 2receives display data relating to the progress of the game from theserver 3, and displays the received display data. In order to implementthe foregoing functions, the portable device 2 includes a devicecommunication unit 21, a device storage unit 22, the operation unit 23,a display unit 24, and a device processing unit 25.

While a multifunctional mobile phone (a so-called “smartphone”) may beassumed as being the portable device 2, the present invention is notlimited to this. The portable device 2 may be, for example, a mobilephone (a so-called “feature phone”), a personal digital assistant (PDA),a portable game machine, a portable music player, a tablet personalcomputer (PC) and the like, as long as the present invention isapplicable thereto.

The device communication unit 21 includes a communication interfacecircuit including an antenna having a sensitivity band in a certainfrequency band, and connects the portable device 2 to a wirelesscommunication network. The device communication unit 21 establishes awireless signal link with the base station 4 by a Wideband Code DivisionMultiple Access (WCDMA) (registered trademark) system or the like via achannel to be assigned by the base station 4, and communicates with thebase station 4. The device communication unit 21 transmits data suppliedfrom the device processing unit 25 to the server 3 or the like. Thedevice communication unit 21 supplies the data received from the server3 or the like to the device processing unit 25.

The device storage unit 22 includes a semiconductor memory device, forexample. The device storage unit 22 stores an operating system program,a driver program, an application program, data, and the like used forprocessing in the device processing unit 25. For example, the devicestorage unit 22 stores, for example, an input device driver program forcontrolling the operation unit 23 and an output device driver programfor controlling the display unit 24, as the driver program. The devicestorage unit 22 stores a program and the like for retrieving anddisplaying display data relating to the progress of the game, as theapplication program. The device storage unit 22 stores display data,video data, image data and the like relating to the progress of thedata, as the data. Further, the device storage unit 22 may storetemporary data relating to certain processing.

The operation unit 23 may be any device capable of operating theportable device 2, for example, a touch pad, a keyboard or the like. Theuser can input letters, numbers, and the like using the operation unit23. When operated by the user, the operation unit 23 generates a signalcorresponding to the operation. The generated signal is supplied to thedevice processing unit 25 as an instruction from the user.

The display unit 24 may be any device capable of displaying a video, animage and the like, for example, a liquid crystal display and an organicelectro-luminescence (EL) display. The display unit 24 displays a video,an image and the like corresponding to video data and image datasupplied from the device processing unit 25.

The device processing unit 25 includes one or a plurality of processorsand their peripheral circuits. The device processing unit 25 is, forexample, a central processing unit (CPU), and integrally controls anoverall operation of the portable device 2. The device processing unit25 controls operations of the device communication unit 21, the displayunit 24, and the like so that various types of processing of theportable device 2 are performed in an appropriate order in accordancewith the programs stored in the device storage unit 22, the operation ofthe operation unit 23, and the like. The device processing unit 25performs processing based on the programs (the operating system program,the driver program, the application program and the like) stored in thedevice storage unit 22. The device processing unit 25 can execute aplurality of programs (application programs and the like) in parallel.

The device processing unit 25 includes at least a browsing executingunit 251. Each of the units is a functional module implemented by aprogram to be executed by the processor included in the deviceprocessing unit 25. Alternatively, each of the units may be provided asa firmware on the portable device 2.

The browsing executing unit 251 retrieves and displays the display datarelating to the progress of the game. In other words, a request toretrieve the display data relating to the progress of the game istransmitted to the server 3 via the device communication unit 21 inresponse to an instruction from the user. The browsing executing unit251 receives corresponding display data from the server 3 via the devicecommunication unit 21. The browsing executing unit 251 generates drawingdata based on the received display data. In other words, the browsingexecuting unit 251 interprets the received display data to specifycontrol data and content data, lays out the specified content dataaccording to the specified control data, and generates the drawing data.Then, the browsing executing unit 251 outputs the generated drawing datato the display unit 24.

FIG. 3 illustrates an example of a schematic configuration of the server3.

The server 3 proceeds the game in response to a request from theportable device 2. The server 3 generates the display data relating tothe progress of the game, and transmits the generated display data tothe portable device 2. In order to implement the foregoing function, theserver 3 includes a server communication unit 31, a server storage unit32, and a server processing unit 33.

The server communication unit 31 includes a communication interfacecircuit for connecting the server 3 to the Internet 7, and communicateswith the Internet 7. The server communication unit 31 supplies the datareceived from the portable device 2 or the like to the server processingunit 33. The server communication unit 31 transmits the data suppliedfrom the server processing unit 33 to the portable device 2 or the like.

The server storage unit 32 includes at least one of a magnetic tapedevice, a magnetic disk device and an optical disk device, for example.The server storage unit 32 stores an operating system program, a driverprogram, an application program, data, and the like used for processingin the server processing unit 33. The server storage unit 32 stores forexample, a game program and the like for advancing the game andgenerating display data relating to its result, as the applicationprogram. The server storage unit 32 stores, as the data, a user table(FIG. 4A) for managing users, a mission table (FIG. 4B) for managingmissions, and an item table (FIG. 4C) for managing items and the like.Further, the server storage unit 32 may store temporary data relating tocertain processing.

FIGS. 4A to 4C illustrate examples of data structures of the varioustypes of tables.

FIG. 4A illustrates an example of the data structure of the user table.The user table includes for each user, a user identifier (ID), a name, alevel, a presented mission ID, an uncleared mission ID, a clearedmission ID, an acquired item ID, a previous finishing date and time, afriend ID and the like. The presented mission ID is an ID of each of themissions to be presented on a mission list for the target user. Theuncleared mission ID is an ID of a mission which has not yet beencleared out of the missions presented on the mission list. The clearedmission ID is an ID of a mission that has already been cleared by thetarget user. The previous finishing date and time is informationrepresenting the date and time of the last time the target user endedthe game.

The friend ID is an ID of another user in a friend status with thetarget user. In the game provided by the game system 1, a friend statuscan be formed among the users. “Friend status” means a relationshipconstituted among users capable of jointly battling with an enemycharacter and sharing a mission in the game, as described below. A usercan have a friend status with a plurality of users. However, an upperlimit may be placed on the number of the other users whom a user canhave a friend status with. A user c in a friend status with a user a isan example of other users associated with the user a.

FIG. 4B illustrates an example of the data structure of the missiontable. The mission table includes for each mission an ID of the mission,a name, a file name of image data, an ID of an enemy character toappear, an ID of an acquirable item and the like.

FIG. 4C illustrates an example of the data structure of the item table.The item table includes for each item an ID of the item, a name, a filename of image data and the like.

The server processing unit 33 includes one or a plurality of processorsand their peripheral circuits. The server processing unit 33 is forexample, a CPU, and integrally controls an overall operation of theserver 3. The server processing unit 33 controls an operation of theserver communication unit 31 or the like so that various types ofprocessing of the server 3 are performed in an appropriate order inaccordance with the programs stored in the server storage unit 32. Theserver processing unit 33 executes processing based on the programsstored in the server storage unit 32 (the operating system program, thedriver program, the application program and the like). The serverprocessing unit 33 can execute the plurality of programs (theapplication program and the like) in parallel.

FIGS. 5A to 5F illustrate examples of a display screen of the portabledevice 2 based on the display data generated by the server 3.

FIGS. 5A and 5B respectively illustrate mission lists 500 in an initialstate of the user a and the user c. Each mission list 500 is displayedbased on list display data received from the server 3. On a screen ofthe user a, dungeons 1 to 3 and items A to C, which can be acquired byclearing the dungeons, are presented as a plurality of missions for theuser a. On a screen of the user c, dungeons 4, 8, and 9 and items D, H,and I, which can be acquired by clearing the dungeons, are presented asa plurality of missions for the user c. In such a manner, differentmissions are presented on the screens of different users. The number ofmissions to be presented may be any number, and in the followingdescription, the number is set to three.

Each dungeon can be selected by pressing corresponding buttons 510, 520,or 530 displayed on the screen. Each of the users confirms the itemsclearly presented on the mission list 500, and operates the portabledevice 2 to select the mission in which the item desired byhimself/herself can be acquired. When any one of the buttons 510, 520,and 530 is pressed, the portable device 2 requests the server 3 toexecute the corresponding mission via the device communication unit 21.The item acquirable in each of the missions may include a plurality oftypes of items. In this case, the plurality of types of items may bepresented on the mission list 500.

FIGS. 5C and 5D respectively illustrate mission lists 500 when the usersa and c have selected the dungeons 1 and 4 in the presented missions andhave cleared the dungeons 1 and 4. On the mission list 500, “cleared” isdisplayed on the button 510 corresponding to the dungeon 1 or 4,indicating that the dungeon 1 or 4 has been cleared. It is not desirablein the progress of a game that an unrestricted number of identical itemscan be acquired. Therefore, when one mission is cleared, in principle,the server 3 disables a corresponding button (the button 510) so thatthe mission may not be executed again. Accordingly, the users a and care not able to select the dungeons 1 and 4 again, respectively.

On the mission list 500 for the user a illustrated in FIG. 5C, themission (dungeon 4) which has been cleared by the other user c in afriend status with the user a, is also presented. Similarly, on themission list 500 for the user c illustrated in FIG. 5D, the mission(dungeon 1) which has been cleared by the other user a in a friendstatus with the user c, is also presented. For example, the user a canalso select the mission which has been presented on the mission list 500for the other user c in a friend status with the user a and has beencleared by the user c, by pressing a button 540 displayed on a lowerpart of the mission list 500. A mission for a second user which has beenpresented together on a mission list for a first user, will behereinafter referred to as a “shared mission”. When the button 540 ispressed, the portable device 2 also requests the server 3 to execute acorresponding mission via the device communication unit 21.

FIG. 5E illustrates the mission list 500 when the user a has cleared allthe missions corresponding to the presented dungeons 1 to 3. When acertain number of (three) missions presented for each user are allcleared, the server 3 enables an exchange button 550 for exchanging thepresented missions. Thus, the user can operate the exchange button 550.When the exchange button 550 is pressed, the portable device 2 requeststhe server 3 to exchange the missions via the device communication unit21. On the mission list 500, the user a can operate the button 540,because he/she has not yet cleared the dungeon 4 serving as the sharedmission.

FIG. 5F illustrates the mission list 500 when the exchange button 550 ispressed, and dungeons 5 to 7 are presented as new missions for the usera. On the mission list 500, the buttons 510, 520, and 530 arere-enabled, and are updated to ones corresponding to the dungeons 5 to7, respectively. On the other hand, when the missions have beenexchanged, the exchange button 550 is disabled. Thus, the user a canselect any one of the dungeons 4 to 7 by pressing the buttons 510 to540, just as on the mission list 500 illustrated in FIG. 5A or 5C.

To implement the foregoing functions, the server processing unit 33includes a control unit 331, a mission generating unit 332, a listingunit 333, a mission executing unit 334, a mission exchanging unit 335,and a shared-mission specifying unit 336. Each of the units is afunctional module implemented by a program to be executed by theprocessor included in the server processing unit 33. Alternatively, eachof the units may be provided as firmware on the server 3.

The control unit 331 controls the progress of a game, and instructs themission generating unit 332, the listing unit 333, the mission executingunit 334, the mission exchanging unit 335, and the shared-missionspecifying unit 336 to perform processing, as needed.

The control unit 331 interprets, when it has received a userauthentication request from the portable device 2 via the servercommunication unit 31, the received user authentication request, andspecifies a user ID and a password. The control unit 331 instructs auser authenticating unit (not illustrated) to perform processing usingthe specified user ID and password as parameters. When the userauthenticating unit has authenticated a user, the control unit 331instructs the listing unit 333 to perform processing using the specifieduser ID as a parameter. The control unit 331 transmits list display datawhich has been returned by the listing unit 333, to the portable device2 via the server communication unit 31.

The control unit 331 instructs, when it has received a mission executionrequest from the portable device 2 via the server communication unit 31,the mission executing unit 334 to perform processing using the receivedmission execution request as a parameter. When the mission executingunit 334 communicates with the portable device 2 a plurality of numbersof times to end execution of a mission, the control unit 331 deletes theID of the mission from the “uncleared mission ID” for the target user inthe user table, and adds the deleted ID to the “cleared mission ID” forthe target user in the user table. Moreover, the control unit 331 callsthe listing unit 333 again at this time, and instructs the listing unit333 to perform processing. The control unit 331 transmits the listdisplay data which has been returned by the listing unit 333, to theportable device 2.

The control unit 331 instructs, when it has received a mission exchangerequest from the portable device 2 via the server communication unit 31,the mission exchanging unit 335 to perform processing using the receivedmission exchange request as a parameter. When the mission exchangingunit 335 terminates mission exchange processing, the control unit 331instructs the listing unit 333 to perform processing again. The controlunit 331 transmits the list display data, which has been returned by thelisting unit 333, to the portable device 2.

The mission generating unit 332 generates a plurality of differentmissions for each user in response to a request issued by the missionexchanging unit 335. The mission generating unit 332 selects, for eachof a geography of a dungeon to be explored by the user, an enemycharacter that appears in the dungeon, and an item acquirable in thedungeon, one of a plurality of candidates to constitute the mission.Thus, the mission generating unit 332 generates a plurality of missions,which differ in a combination of a geography of a dungeon, an appearingenemy character, and an acquirable item, for example.

If, for example, the game system 1 provides a game including tenmissions in all to each of the users, the ten missions differ dependingon the user. Thus, in a general game, a plurality of identical missionsis provided to all of the users, but in the game provided by the gamesystem 1, different missions are provided to each user. The missiongenerating unit 332 may generate, for example, individual missions atrandom or generate different missions for each of the users according toany regularity.

The mission generating unit 332 refers to the user table using the userID as a key, specifies the level of the target user, and then generatesmissions. The higher the level is, the higher the degree of difficultyof the generated mission is. The mission having a high degree ofdifficulty is, for example, a mission in which a stronger enemycharacter appears and in which the user consumes more physical strengthto clear. The mission generating unit 332 sets items acquirable in eachof the missions. The higher the degree of difficulty of the mission is,the more valuable the items to be acquired in the mission are and thelarger the number of the items to be acquired in the mission becomes.The mission generating unit 332 adds information about the generatedmission to the mission table.

The listing unit 333 presents a list of the missions which have beengenerated by the mission generating unit 332, to the portable device 2of each of the users via the server communication unit 31. In order toachieve such function, the listing unit 333 generates list display datafor displaying the mission list 500 illustrated in FIGS. 5A to 5F on theportable device 2. Specifically, the listing unit 333 refers to the usertable using the user ID as a key, and specifies the IDs of (e.g., three)missions generated for the target user and to be presented on themission list 500 and whether the missions have been cleared. The listingunit 333 causes the shared-mission specifying unit 336 to specify ashared mission to be presented on the mission list 500. Further, thelisting unit 333 refers to the mission table using each of the specifiedmission IDs as a key, and specifies the item acquirable in each mission.

The listing unit 333 generates list display data so that names ofrespective missions, an image, items acquirable by clearing themissions, data for indicating whether each of the missions has beencleared, and buttons for selecting respective missions are displayed.The listing unit 333 enables, for an uncleared mission, a button of themission, and disables, for a cleared mission, a button of the mission.Particularly for a shared mission, a button is displayed so that theuser can select the mission only within a certain effective time toprevent the number of missions to be presented from increasingunlimitedly.

Further, the listing unit 333 presents an operational element forupdating the missions included in the mission list 500 to other missionsaccording to the progress of the presented missions. Specifically, thelisting unit 333 enables, when the three missions currently presentedare all cleared missions, the exchange button 550 illustrated in FIG. 5Efor exchanging the missions. The listing unit 333 may disable theexchange button 550 when at least one of the missions currentlypresented has been cleared. The exchange button 550 is an example of theoperational element.

The mission executing unit 334 communicates with the portable device 2 aplurality of times to execute the mission when receiving the missionexecution request from the portable device 2 caused by the useroperating a button corresponding to one mission on the mission list 500.The mission may be executed by the device processing unit 25 in theportable device 2 without providing the mission executing unit 334 inthe server 3.

The mission exchanging unit 335 exchanges, when receiving a missionexchange request from the portable device 2 caused by the user operatingthe exchange button 550 in the mission list 500, a mission in themission list 500 for another mission generated by the mission generatingunit 332 for the target user.

Specifically, the mission exchanging unit 335 causes, when the useroperates the exchange button 550 in the mission list, the missiongenerating unit 332 to generate a new mission for the user. The missionexchanging unit 335 deletes the ID of the mission from the “presentedmission ID” for the target user in the user table, and adds the ID ofthe newly generated mission to the “uncleared mission ID” and the“presented mission ID” for the target user. When the mission exchangingunit 335 exchanges the missions, the possibility that the user canselect a mission he/she likes becomes higher, increasing the user's willto continue the game.

As described above, in the game system 1, a plurality of new missionsare presented each time a certain period (e.g., 24 hours) has elapsed.However, the mission exchanging unit 335 exchanges the missionspresented on the mission list 500 regardless of whether the certainperiod has elapsed, in response to the user operating the exchangebutton 550. In other words, since the exchange button 550 is disabledeach time the three presented missions are cleared, the user who hascleared the missions quickly can select a new mission without waiting,for example, 24 hours.

The mission exchanging unit 335 may perform exchange processing not onlyfor the missions generated for each of the users but also for a sharedmission. The missions to be exchanged by the mission exchanging unit 335may include a mission cleared once by the user. In other words, the samemission may be presented again by exchanging the missions. In this case,the user can re-execute the mission that has been cleared once.

The shared-mission specifying unit 336 specifies a mission presented toa portable device of a second user in a friend status with a first userso that the shared mission is presented on a portable device of thefirst user. A first user (himself/herself) and one of second users(other users) are described below as the user a and the user c,respectively.

The shared-mission specifying unit 336 first refers to the user tableusing the user ID of the user a as a key, and specifies other users in afriend status with the user a. The shared-mission specifying unit 336may present shared missions for all the users in a friend status withthe user a on the mission list 500 for the user a. When the number ofusers is large, however, the shared missions are presented only for thenumber of users within a certain upper limit. The shared-missionspecifying unit 336 sets the upper limit of the number of users forwhich the shared missions are presented to four, for example, and makesrespective missions cleared by the four users as the shared missions. Asthe four users, the shared-mission specifying unit 336 selects, out ofthe users in a friend status with the user a, the two users whoseprevious finishing date and time are most and second most recent and twousers whose previous finishing date and time are the oldest and thesecond oldest. In other words, the shared-mission specifying unit 336selects the user who has most recently played the game and the user whohas not recently played the game as the other users for which the sharedmission is to be presented on the mission list 500 for the user a.

The shared-mission specifying unit 336 refers to the user table usingthe user ID of the selected other user as a key, selects one of clearedmissions for the user, and specifies the selected cleared mission as ashared mission. A shared mission is selectable by the user only within acertain effective time. Thus, for each of the users, the shared-missionspecifying unit 336 specifies one mission which has most recently beencleared by the user, for example, as a shared mission. Alternatively,the shared-mission specifying unit 336 may select one of the unclearedmissions for the user and specify the selected uncleared mission as ashared mission.

Presenting a shared mission on the mission list 500 may enable a user toacquire a desired item in the shared mission although the desired itemis not able to acquire in his/her own mission, for example. A user in afriend status with more users can more easily acquire items because thenumber of missions to be shared increases. When the shared missions arepresented on the mission list 500, therefore, a chance for the user toselect the missions further increases, which increases the user's willto continue the game.

A dungeon in which an item desired by a user can be acquired maypreferentially be displayed. For example, to enable the user to reliablyacquire the item he/she desires, a mission which the user was unable toclear in the past, is managed in the server 3, and the shared-missionspecifying unit 336 may preferentially extract, out of a plurality ofcandidates of shared missions, the mission that the user was unable toclear in the past.

A mission and an item which can be acquired when the mission has beencleared are managed in association with each other in the server 3 (themission table illustrated in FIG. 4B). When a user designates a desireditem in advance, the shared-mission specifying unit 336 may becontrolled to preferentially extract, out of a plurality of candidatesof shared missions, a mission in which the item designated by the usercan be acquired.

Since the mission generating unit 332 generates missions correspondingto the level of a user, a shared mission is a mission corresponding tothe level of another user in a friend status with the user a. If anotheruser has a higher level than that of the user a, for example, a missionwhich is not presented at the level of the user a may be presented as ashared mission. In this case, it is difficult for the user a to clearthe shared mission, but if the user a clears the shared mission, theuser a can acquire more items than when the user a clears a missiongenerated for himself/herself.

In order to present missions with a higher level of difficulty, theshared-mission specifying unit 336 may set a mission which has beencleared by the user having a higher level than that of the user a out ofthe plurality of users in a friend status with the user a, as a sharedmission. Alternatively, the shared-mission specifying unit 336 may set,as a shared mission, a mission for another user in a certainrelationship other than the friend status such as a user designated bythe user a.

Further, the number of shared missions to be presented is not limited toone but may be plural per user in a friend status with the user a. Forexample, a parameter such as a degree of intimacy may be set between auser and another user in a friend status therewith, and the number ofshared missions to be presented and the type and the number of itemsacquirable in the shared missions may be made different depending on theparameter.

The shared-mission specifying unit 336 push-notifies the portable deviceof the second user via the server communication unit 31 that a missionpresented on the portable device of the second user (user c) in a friendstatus with the first user (user a) has also been presented on theportable device of the first user. In this case, the shared-missionspecifying unit 336 clearly presents the user name of the first user(user a) and push-notifies the second user of the user name. Thus, auser becomes more interested and motivated to the game when “Mission hasbeen shared by user a”, for example, is notified to clearly present aone-to-one relationship between users than when “New mission hasstarted” is simply notified simultaneously from the server 3 to users.Particularly, the shared-mission specifying unit 336 selects a user whohas not recently played the game as the second user, to encourage theuser to participate in the game.

FIG. 6 illustrates an example of an operation sequence of the gamesystem 1. The operation sequence described below is executed mainly bythe device processing unit 25 and the server processing unit 33 based onprograms previously stored in the device storage unit 22 and the serverstorage unit 32, in cooperation with each of the units in the portabledevice 2 and the server 3.

The user a instructs the device processing unit 25 to execute a programfor retrieving and displaying display data relating to the progress ofthe game via the operation unit 23. The device processing unit 25 startsprocessing based on this program. In other words, the browsing executingunit 251 to be implemented by the program transmits, when the user a hasinput a user ID and a password via the operation unit 23, a userauthentication request including the input user ID, password and thelike to the server 3 via the device communication unit 21 (step S600).

The control unit 331 interprets, when receiving the user authenticationrequest via the server communication unit 31 from the portable device 2,the received user authentication request and specifies the user ID andthe password. The control unit 331 instructs a user authenticating unit(not illustrated) to perform processing using the specified user ID andpassword as parameters (step S602). The control unit 331 instructs, whenthe user authenticating unit has authenticated the user, the listingunit 333 to perform processing using the specified user ID as aparameter (step S604).

The control unit 331 transmits list display data which has been returnedby the listing unit 333 to the portable device 2 via the servercommunication unit 31 (step S606). The browsing executing unit 251 inthe portable device 2 generates, when receiving the list display datafrom the server 3 via the device communication unit 21, drawing databased on the received list display data. The browsing executing unit 251outputs the generated drawing data to the display unit 24 to display amission list thereon (step S608).

When an execution instruction of a mission has been input on the missionlist by the user via the operation unit 23, the browsing executing unit251 transmits a content of the instruction and the user ID to the server3 via the device communication unit 21 (step S610). The control unit 331of the server 3 instructs, when receiving the mission execution requestfrom the portable device 2 via the server communication unit 31, themission executing unit 334 to perform processing using the receivedmission execution request as a parameter (step S612).

When the mission executing unit 334 terminates the mission executionprocessing, the control unit 331 instructs the listing unit 333 toperform processing (step S614), just as in step S604, and transmits listdisplay data which has been returned by the listing unit 333 to theportable device 2 (step S616), just as in step S606. The browsingexecuting unit 251 of the portable device 2 causes the display unit 24to display a mission list on the display unit 24 (step S618), just as instep S608.

When an exchange instruction of the missions has been input on themission list by the user via the operation unit 23, the browsingexecuting unit 251 transmits a content of the instruction and the userID to the server 3 via the device communication unit 21 (step S620). Thecontrol unit 331 of the server 3 instructs, when receiving a missionexchange request from the portable device 2 via the server communicationunit 31, the mission exchanging unit 335 to perform processing using thereceived mission exchange request as a parameter (step S622).

The control unit 331 instructs, when the mission exchanging unit 335terminates the mission exchange processing, the listing unit 333 toperform processing (step S624), just as in step S604. The control unit331 transmits list display data which has been returned by the listingunit 333 to the portable device 2 (step S626), just as in step S606. Thebrowsing executing unit 251 of the portable device 2 causes the displayunit 24 to display a mission list (step S628). Subsequently, processingis similarly performed.

FIG. 7A illustrates an example of an operation flow of the listing unit333.

The listing unit 333 first specifies an uncleared mission for a targetuser (step S700). In this case, the listing unit 333 refers to the usertable using the user ID of the target user as a key, and specifies thethree presented mission IDs and the uncleared mission IDs. Further, thelisting unit 333 refers to the mission table using each of the specifiedpresented missions IDs as a key, and also specifies the item acquirablein the corresponding mission.

If all the three missions which have been specified in step 700 havebeen cleared (i.e., there is no uncleared mission ID) (YES in stepS702), the listing unit 333 disables the exchange button 550 (stepS704). On the other hand, if the three missions which have beenspecified in step S700 includes an uncleared mission (NO in step S702),the listing unit 333 keeps the exchange button 550 disabled withoutexecuting step S704.

The listing unit 333 then causes the shared-mission specifying unit 336to specify a shared mission to be presented on the mission list (stepS706). The listing unit 333 generates list display data for displaying amission list including names of respective missions, images, acquirableitems, data for indicating whether each of the missions has beencleared, and buttons for selecting respective missions (step S708). Thelisting unit 333 returns the list display data to the control unit 331(step S710), and then terminates the processing.

In the operation flow illustrated in FIG. 7A, the shared mission isspecified in step S706 each time list retrieval processing is performed.However, since the shared-mission specifying unit 336 specifies themission which has most recently been cleared by each user as the sharedmission, for example, even if step S706 is executed, the shared missionpresented on the mission list may not be changed.

FIG. 7B illustrates an example of an operation flow of the missionexchanging unit 335.

The mission exchanging unit 335 first causes the mission generating unit332 to newly generate missions for the target user (step S720). Themission exchanging unit 335 updates the presented mission IDs for thetarget user in the user table with IDs of the missions newly generated(step S722). Further, the mission exchanging unit 335 adds the IDs ofthe missions newly generated to the uncleared mission IDs for the targetuser in the user table (step S724). Then, the mission exchanging unit335 terminates the processing.

FIG. 8 illustrates an example of an operation flow of the shared-missionspecifying unit 336.

The shared-mission specifying unit 336 first refers to the user tableusing the user ID of a target user as a key, and extracts users in afriend status with the target user (step S800). The shared-missionspecifying unit 336 selects one of the users in the friend status, whohave been extracted in step S800, in accordance with a certaincriterion, for example, the user whose previous finishing date and timeis most recent or whose previous finishing date and time is the oldest(step S802). The shared-mission specifying unit 336 refers to the usertable using the user ID of the selected other user as a key, andspecifies cleared missions for the selected user (step S804). Further,the shared-mission specifying unit 336 selects, out of the clearedmissions which have been specified in step 5804, the mission that hasmost recently been cleared, and specifies the selected mission as amission to be shared (step S806).

When the number of users for which the shared missions are presented hasnot reached a certain upper limit yet (NO in step S808), the processingreturns to step S802. On the other hand, when the number of users forwhich the shared missions are presented has reached the upper limit (YESin step S808), the shared-mission specifying unit 336 returns themissions specified thus far as shared missions to the listing unit 333(step S810), and terminates the processing.

As has been described above, in the game system 1, the missiongenerating unit 332 generates separate missions and provides thegenerated missions to each of the users, and the mission exchanging unit335 exchanges the missions on the mission list so that a chance for theuser to select the missions increases, making it possible to maintainand increase the user's will to continue the game.

In the operation flow illustrated in FIG. 7A, once the exchange button550 is pressed, the exchange button 550 will not be disabled as long asthe presented missions are all cleared. However, even after beingpressed, the exchange button 550 may be pressed many times within acertain period (e.g., 24 hours).

A computer program for causing a computer to execute the respectivefunctions of the device processing unit 25 and the server processingunit 33 may be provided in a form recorded on a computer readablerecording medium such as a magnetic recording medium or an opticalrecording medium.

It should be understood that various changes, substitutions, andmodifications can be made to the present invention by those skilled inthe art without departing from the spirit and scope of the presentinvention.

The preceding description has been presented only to illustrate anddescribe exemplary embodiments of the present invention. It is notintended to be exhaustive or to limit the invention to any precise formdisclosed. It will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope. Therefore, it is intended that the invention not belimited to the particular embodiment disclosed as the best modecontemplated for carrying out this invention, but that the inventionwill include all embodiments falling within the scope of the claims. Theinvention may be practiced otherwise than is specifically explained andillustrated without departing from its spirit or scope.

What is claimed is:
 1. A method for providing a game to a plurality ofuser devices from a server device having a storage unit for storing userinformation relating to a plurality of users, the method comprising thesteps of: (a) generating a plurality of missions for each of theplurality of users, respectively; (b) transmitting, to a first userdevice, displaying information for presenting a list of the missionsgenerated for a first user on the first user device, the presented listindicating each of the missions and an item which the first user canacquire by clearing the mission, in association with each other; (c)receiving an identifier of an item from the first user device; and (d)updating the displaying information so that a first mission included inthe presented list is replaced with a second mission generated for thefirst user, wherein the second mission is a mission in which the itemspecified by the received identifier can be acquired.
 2. The methodaccording to claim 1, wherein the storage unit stores level informationrelating to skill levels of the plurality of users, and in step (a), theserver device generates a mission for a user so that either the value orthe number of items which the user can acquire by clearing the missionincreases as the skill level of the user rises.
 3. The method accordingto claim 1, wherein the displaying information transmitted in step (b)includes data for displaying an operational element in the presentedlist, the operational element being used for updating a mission includedin the presented list, and in step (d), the displaying information isupdated in response to an operation of the operational element, themethod further comprising the step of transmitting, to the first userdevice, second displaying information for presenting a new list on thefirst user device, the new list indicating the second mission and anitem which the first user can acquire by clearing the second mission, inassociation with each other.
 4. The method according to claim 3, whereinthe displaying information transmitted in step (b) includes data fordisplaying the operational element in the presented list so that thefirst user can operate the operational element a plurality of timesregardless of progress of the missions included in the presented list,and in step (d), the displaying information is updated each time theoperational element is operated.
 5. The method according to claim 1,further comprising: storing, for each of the plurality of users, statusinformation indicating a degree of intimacy between the user and anotheruser who has a game-mission sharing relationship with the user, in thestorage unit; and selecting a mission presented on a second user deviceof a second user who has the game-mission sharing relationship with thefirst user as a shared mission which the first user can also play,wherein the displaying information transmitted in step (b) includes datafor presenting, in the list, the shared mission together with a missiongenerated for the first user, and either the number of shared missionspresented in the list or an item which the first user can acquire in theshared mission is changed depending on the degree of intimacy betweenthe first user and the second user.
 6. A non-transitory storage mediumhaving stored therein a control program for a server device providing agame to a plurality of user devices, the server device having a storageunit for storing user information relating to a plurality of users, thecontrol program, when executed by the server device, causing the serverdevice to perform a process, the process comprising: generating aplurality of missions for each of the plurality of users, respectively;transmitting, to a first user device, displaying information forpresenting a list of the missions generated for a first user on thefirst user device, the presented list indicating each of the missionsand an item which the first user can acquire by clearing the mission, inassociation with each other; receiving an identifier of an item from thefirst user device; and updating the displaying information so that afirst mission included in the presented list is replaced with a secondmission generated for the first user, wherein the second mission is amission in which the item specified by the received identifier can beacquired.
 7. A server device for providing a game to a plurality of userdevices, the server device comprising: a storage unit for storing userinformation relating to a plurality of users; a generating unit forgenerating a plurality of missions for each of the plurality of users,respectively; a transmitting unit for transmitting, to a first userdevice, displaying information for presenting a list of the missionsgenerated for a first user on the first user device, the presented listindicating each of the missions and an item which the first user canacquire by clearing the mission, in association with each other; areceiving unit for receiving an identifier of an item from the firstuser device; and a processing unit for updating the displayinginformation so that a first mission included in the presented list isreplaced with a second mission generated for the first user, wherein thesecond mission is a mission in which the item specified by the receivedidentifier can be acquired.